Documents disponibles écrits par cet auteur

Heat transfer characteristics of falling film process on coated division tubes / Qunchang Wang in Industrial & engineering chemistry research, Vol. 49 N° 14 (Juillet 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6622–6629 Titre : Heat transfer characteristics of falling film process on coated division tubes : effect of the surface configurations Type de document : texte imprimé Auteurs : Qunchang Wang, Auteur ; Xuehu Ma, Auteur ; Zhong Lan, Auteur Année de publication : 2010 Article en page(s) : pp. 6622–6629 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heat  transfer Résumé : In general, mixing of solution could refresh the interface of bulk liquid, and hence lead to the more efficient heat transfer within the liquid film. By using the high speed video camera and thermal imaging technique, the flow patterns and heat transfer characteristics of liquid film on coated division tubes, on which the hydrophobically coated regions and the bare regions presented alternately, were investigated experimentally. Flow visualization revealed that the minimum wetting rate increases with the increase in the effective contact angle of this surface. The cumulative liquid ring was observed at the boundary of bare region and coated region. The fluctuations of liquid film temperature were measured at different liquid film mass flow rates and the initial fluid temperatures. The temperature fluctuation periods on the coated division tube increased with the decrease of flow rate and initial liquid temperature. The liquid film surface temperature on the coated division tubes was higher than that on the uncoated bare tube at the same falling film position; that is, the heat transfer in the liquid film on the coated division tube was more efficient than that on the uncoated bare tube. The disturbance of falling liquid film was strengthened from the existence of the coated region, resulting in stronger mixing that drove the liquid particles from the internal of the liquid film to the interface, which greatly contributed to the enhancement of heat and mass transfer. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018676 [article] Heat transfer characteristics of falling film process on coated division tubes : effect of the surface configurations [texte imprimé] / Qunchang Wang, Auteur ; Xuehu Ma, Auteur ; Zhong Lan, Auteur . - 2010 . - pp. 6622–6629. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 14 (Juillet 2010) . - pp. 6622–6629 Mots-clés : Heat  transfer Résumé : In general, mixing of solution could refresh the interface of bulk liquid, and hence lead to the more efficient heat transfer within the liquid film. By using the high speed video camera and thermal imaging technique, the flow patterns and heat transfer characteristics of liquid film on coated division tubes, on which the hydrophobically coated regions and the bare regions presented alternately, were investigated experimentally. Flow visualization revealed that the minimum wetting rate increases with the increase in the effective contact angle of this surface. The cumulative liquid ring was observed at the boundary of bare region and coated region. The fluctuations of liquid film temperature were measured at different liquid film mass flow rates and the initial fluid temperatures. The temperature fluctuation periods on the coated division tube increased with the decrease of flow rate and initial liquid temperature. The liquid film surface temperature on the coated division tubes was higher than that on the uncoated bare tube at the same falling film position; that is, the heat transfer in the liquid film on the coated division tube was more efficient than that on the uncoated bare tube. The disturbance of falling liquid film was strengthened from the existence of the coated region, resulting in stronger mixing that drove the liquid particles from the internal of the liquid film to the interface, which greatly contributed to the enhancement of heat and mass transfer. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9018676

Oscillating and bouncing off of condensate droplets on a vertical superhydrophobic surface / Xuehu Ma in Journal of heat transfer, Vol. 134 N° 8 (special issue) (Août 2012) 

Public ISBD [article]  in Journal of heat transfer > Vol. 134 N° 8 (special issue) (Août 2012) . - 01 p. Titre : Oscillating and bouncing off of condensate droplets on a vertical superhydrophobic surface Type de document : texte imprimé Auteurs : Xuehu Ma, Auteur ; Sifang Wang, Auteur ; Zhong Lan, Auteur Année de publication : 2012 Article en page(s) : 01 p. Note générale : heat transfer Langues : Anglais (eng) Note de contenu : Photogallery DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000008 [...] [article] Oscillating and bouncing off of condensate droplets on a vertical superhydrophobic surface [texte imprimé] / Xuehu Ma, Auteur ; Sifang Wang, Auteur ; Zhong Lan, Auteur . - 2012 . - 01 p. heat transfer Langues : Anglais (eng) in Journal of heat transfer > Vol. 134 N° 8 (special issue) (Août 2012) . - 01 p. Note de contenu : Photogallery DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000008 [...]

Wetting mode evolution of steam dropwise condensation on superhydrophobic surface in the presence of noncondensable gas / Xuehu Ma in Journal of heat transfer, Vol. 134 N° 2 (Fevrier 2012) 

Public ISBD [article]  in Journal of heat transfer > Vol. 134 N° 2 (Fevrier 2012) . - 09 p. Titre : Wetting mode evolution of steam dropwise condensation on superhydrophobic surface in the presence of noncondensable gas Type de document : texte imprimé Auteurs : Xuehu Ma, Auteur ; Sifang Wang, Auteur ; Zhong Lan, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Heat transfer Langues : Anglais (eng) Mots-clés : Air  Condensation  Contact  angle  Drops  Heat  transfer  Hydrophobicity  Steam  Surface  roughness  Wetting Index. décimale : 536 Chaleur. Thermodynamique Résumé : It is well known that heat transfer in dropwise condensation (DWC) is superior to that in filmwise condensation (FWC) by at least one order of magnitude. Surfaces with larger contact angle (CA) can promote DWC heat transfer due to the formation of “bare” condensation surface caused by the rapid removal of large condensate droplets and high surface replenishment frequency. Superhydrophobic surfaces with high contact angle (> 150°) of water and low contact angle hysteresis (< 5°) seem to be an ideal condensing surface to promote DWC and enhance heat transfer, in particular, for the steam-air mixture vapor. In the present paper, steam DWC heat transfer characteristics in the presence of noncondensable gas (NCG) were investigated experimentally on superhydrophobic and hydrophobic surfaces including the wetting mode evolution on the roughness-induced superhydrophobic surface. It was found that with increasing NCG concentration, the droplet conducts a transition from the Wenzel to Cassie-Baxter mode. And a new condensate wetting mode—a condensate sinkage mode—was observed, which can help to explain the effect of NCG on the condensation heat transfer performance of steam-air mixture on a roughness-induced superhydrophobic SAM-1 surface. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000002 [...] [article] Wetting mode evolution of steam dropwise condensation on superhydrophobic surface in the presence of noncondensable gas [texte imprimé] / Xuehu Ma, Auteur ; Sifang Wang, Auteur ; Zhong Lan, Auteur . - 2012 . - 09 p. Heat transfer Langues : Anglais (eng) in Journal of heat transfer > Vol. 134 N° 2 (Fevrier 2012) . - 09 p. Mots-clés : Air  Condensation  Contact  angle  Drops  Heat  transfer  Hydrophobicity  Steam  Surface  roughness  Wetting Index. décimale : 536 Chaleur. Thermodynamique Résumé : It is well known that heat transfer in dropwise condensation (DWC) is superior to that in filmwise condensation (FWC) by at least one order of magnitude. Surfaces with larger contact angle (CA) can promote DWC heat transfer due to the formation of “bare” condensation surface caused by the rapid removal of large condensate droplets and high surface replenishment frequency. Superhydrophobic surfaces with high contact angle (> 150°) of water and low contact angle hysteresis (< 5°) seem to be an ideal condensing surface to promote DWC and enhance heat transfer, in particular, for the steam-air mixture vapor. In the present paper, steam DWC heat transfer characteristics in the presence of noncondensable gas (NCG) were investigated experimentally on superhydrophobic and hydrophobic surfaces including the wetting mode evolution on the roughness-induced superhydrophobic surface. It was found that with increasing NCG concentration, the droplet conducts a transition from the Wenzel to Cassie-Baxter mode. And a new condensate wetting mode—a condensate sinkage mode—was observed, which can help to explain the effect of NCG on the condensation heat transfer performance of steam-air mixture on a roughness-induced superhydrophobic SAM-1 surface. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000002 [...]